Iron Deficiency Anemia of Digestive Origin without Overt Hemorrhage: From Celiac Disease and Helicobacter pylori to Pernicious Anemia, Tea Consumption, Pica, Heyde Syndrome, and Hereditary Hemorrhagic Telangiectasia
Iron deficiency anemia (IDA) is the most prevalent nutritional deficiency worldwide, yet its etiology
frequently escapes detection when overt gastrointestinal hemorrhage is absent. A heterogeneous
spectrum of digestive conditions — operating through malabsorption, achlorhydria, competitive luminal
inhibition, chronic mucosal inflammation, and acquired coagulopathy — accounts for a clinically
important and systematically under investigated subset of IDA. This review examines eight major
non-hemorrhagic or occult-hemorrhagic digestive causes of IDA: celiac disease, Helicobacter pylori
gastritis, autoimmune atrophic gastritis and pernicious anemia (Biermer disease), dietary polyphenol
consumption (tea), pica and pagophagia, Heyde syndrome, and hereditary hemorrhagic telangiectasia
(Rendu-Osler-Weber disease). For each condition, we detail the pathophysiology of iron depletion,
the optimal diagnostic strategy integrating serological, endoscopic, and genetic approaches, and the
evidence-based therapeutic management including the pivotal role of intravenous iron formulations
when oral supplementation is insufficient or contraindicated. A unified diagnostic algorithm is proposed
to guide clinicians in the systematic evaluation of IDA without evident hemorrhage. Recognition of
these non-hemorrhagic causes is essential to avoid diagnostic delay, minimize transfusion exposure, and
ensure targeted treatment of the underlying condition alongside iron repletion.
